linux/kernel
Linus Torvalds 5628b8de12 Random number generator changes for Linux 5.18-rc1.
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Merge tag 'random-5.18-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator updates from Jason Donenfeld:
 "There have been a few important changes to the RNG's crypto, but the
  intent for 5.18 has been to shore up the existing design as much as
  possible with modern cryptographic functions and proven constructions,
  rather than actually changing up anything fundamental to the RNG's
  design.

  So it's still the same old RNG at its core as before: it still counts
  entropy bits, and collects from the various sources with the same
  heuristics as before, and so forth. However, the cryptographic
  algorithms that transform that entropic data into safe random numbers
  have been modernized.

  Just as important, if not more, is that the code has been cleaned up
  and re-documented. As one of the first drivers in Linux, going back to
  1.3.30, its general style and organization was showing its age and
  becoming both a maintenance burden and an auditability impediment.

  Hopefully this provides a more solid foundation to build on for the
  future. I encourage you to open up the file in full, and maybe you'll
  remark, "oh, that's what it's doing," and enjoy reading it. That, at
  least, is the eventual goal, which this pull begins working toward.

  Here's a summary of the various patches in this pull:

   - /dev/urandom and /dev/random now do the same thing, per the patch
     we discussed on the list. I think this is worth trying out. If it
     does appear problematic, I've made sure to keep it standalone and
     revertible without any conflicts.

   - Fixes and cleanups for numerous integer type problems, locking
     issues, and general code quality concerns.

   - The input pool's LFSR has been replaced with a cryptographically
     secure hash function, which has security and performance benefits
     alike, and consequently allows us to count entropy bits linearly.

   - The pre-init injection now uses a real hash function too, instead
     of an LFSR or vanilla xor.

   - The interrupt handler's fast_mix() function now uses one round of
     SipHash, rather than the fake crypto that was there before.

   - All additions of RDRAND and RDSEED now go through the input pool's
     hash function, in part to mitigate ridiculous hypothetical CPU
     backdoors, but more so to have a consistent interface for ingesting
     entropy that's easy to analyze, making everything happen one way,
     instead of a potpourri of different ways.

   - The crng now works on per-cpu data, while also being in accordance
     with the actual "fast key erasure RNG" design. This allows us to
     fix several boot-time race complications associated with the prior
     dynamically allocated model, eliminates much locking, and makes our
     backtrack protection more robust.

   - Batched entropy now erases doled out values so that it's backtrack
     resistant.

   - Working closely with Sebastian, the interrupt handler no longer
     needs to take any locks at all, as we punt the
     synchronized/expensive operations to a workqueue. This is
     especially nice for PREEMPT_RT, where taking spinlocks in irq
     context is problematic. It also makes the handler faster for the
     rest of us.

   - Also working with Sebastian, we now do the right thing on CPU
     hotplug, so that we don't use stale entropy or fail to accumulate
     new entropy when CPUs come back online.

   - We handle virtual machines that fork / clone / snapshot, using the
     "vmgenid" ACPI specification for retrieving a unique new RNG seed,
     which we can use to also make WireGuard (and in the future, other
     things) safe across VM forks.

   - Around boot time, we now try to reseed more often if enough entropy
     is available, before settling on the usual 5 minute schedule.

   - Last, but certainly not least, the documentation in the file has
     been updated considerably"

* tag 'random-5.18-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (60 commits)
  random: check for signal and try earlier when generating entropy
  random: reseed more often immediately after booting
  random: make consistent usage of crng_ready()
  random: use SipHash as interrupt entropy accumulator
  wireguard: device: clear keys on VM fork
  random: provide notifier for VM fork
  random: replace custom notifier chain with standard one
  random: do not export add_vmfork_randomness() unless needed
  virt: vmgenid: notify RNG of VM fork and supply generation ID
  ACPI: allow longer device IDs
  random: add mechanism for VM forks to reinitialize crng
  random: don't let 644 read-only sysctls be written to
  random: give sysctl_random_min_urandom_seed a more sensible value
  random: block in /dev/urandom
  random: do crng pre-init loading in worker rather than irq
  random: unify cycles_t and jiffies usage and types
  random: cleanup UUID handling
  random: only wake up writers after zap if threshold was passed
  random: round-robin registers as ulong, not u32
  random: clear fast pool, crng, and batches in cpuhp bring up
  ...
2022-03-21 14:55:32 -07:00
..
bpf bpf: Add schedule points in batch ops 2022-02-17 10:48:26 -08:00
cgroup Merge branch 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2022-02-22 16:14:35 -08:00
configs configs/debug: restore DEBUG_INFO=y for overriding 2022-03-17 11:02:13 -07:00
debug kdb: Adopt scheduler's task classification 2021-11-03 17:21:37 +00:00
dma swiotlb: rework "fix info leak with DMA_FROM_DEVICE" 2022-03-07 11:26:02 -08:00
entry signal, x86: Delay calling signals in atomic on RT enabled kernels 2022-03-04 14:58:54 +01:00
events perf: Fix list corruption in perf_cgroup_switch() 2022-02-06 22:37:27 +01:00
futex Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
gcov gcov: Remove compiler version check 2021-12-02 17:25:21 +09:00
irq irqchip updates for 5.18 2022-03-14 10:23:22 +01:00
kcsan KCSAN updates for v5.17 2022-01-11 09:51:26 -08:00
livepatch Livepatching changes for 5.17 2022-01-16 10:08:13 +02:00
locking lockdep: Correct lock_classes index mapping 2022-02-11 23:30:02 +01:00
power PM: suspend: fix return value of __setup handler 2022-03-01 18:55:07 +01:00
printk printk: Fix incorrect __user type in proc_dointvec_minmax_sysadmin() 2022-02-03 11:27:38 -08:00
rcu RCU pull request for v5.18 2022-03-21 14:00:56 -07:00
sched Merge back cpufreq changes for v5.18. 2022-02-28 20:47:57 +01:00
time tick/rcu: Stop allowing RCU_SOFTIRQ in idle 2022-03-07 23:01:34 +01:00
trace Minor tracing fixes: 2022-03-10 17:23:08 -08:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
acct.c kernel: remove spurious blkdev.h includes 2021-10-18 06:17:01 -06:00
async.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-03 11:20:34 -08:00
audit_fsnotify.c fsnotify: clarify contract for create event hooks 2021-10-27 12:32:34 +02:00
audit_tree.c audit: use struct_size() helper in kmalloc() 2021-12-14 17:39:42 -05:00
audit_watch.c \n 2021-11-06 16:43:20 -07:00
audit.c audit: improve audit queue handling when "audit=1" on cmdline 2022-01-25 13:22:51 -05:00
audit.h audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
auditfilter.c audit/stable-5.17 PR 20220110 2022-01-11 13:08:21 -08:00
auditsc.c audit: don't deref the syscall args when checking the openat2 open_how::flags 2022-02-09 16:04:26 -05:00
backtracetest.c
bounds.c
capability.c
cfi.c cfi: Use rcu_read_{un}lock_sched_notrace 2021-08-11 13:11:12 -07:00
compat.c arch: remove compat_alloc_user_space 2021-09-08 15:32:35 -07:00
configs.c
context_tracking.c
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
cpu.c random: clear fast pool, crng, and batches in cpuhp bring up 2022-02-21 21:14:21 +01:00
crash_core.c kernel/crash_core: suppress unknown crashkernel parameter warning 2021-12-25 12:20:55 -08:00
crash_dump.c
cred.c ucounts: Base set_cred_ucounts changes on the real user 2022-02-17 09:11:02 -06:00
delayacct.c delayacct: track delays from memory compact 2022-01-20 08:52:55 +02:00
dma.c
exec_domain.c
exit.c fork: Move task stack accounting to do_exit() 2022-02-22 22:25:02 +01:00
extable.c extable: use is_kernel_text() helper 2021-11-09 10:02:51 -08:00
fail_function.c
fork.c Core code updates: 2022-03-21 12:37:33 -07:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
gen_kheaders.sh kbuild: clean up ${quiet} checks in shell scripts 2021-05-27 04:01:50 +09:00
groups.c groups: simplify struct group_info allocation 2021-02-26 09:41:03 -08:00
hung_task.c hung_task: move hung_task sysctl interface to hung_task.c 2022-01-22 08:33:34 +02:00
iomem.c
irq_work.c irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT 2021-10-15 11:25:18 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c Livepatching changes for 5.17 2022-01-16 10:08:13 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt signal, x86: Delay calling signals in atomic on RT enabled kernels 2022-03-04 14:58:54 +01:00
kcov.c kcov: replace local_irq_save() with a local_lock_t 2021-11-09 10:02:52 -08:00
kexec_core.c exit: Move oops specific logic from do_exit into make_task_dead 2021-12-13 12:04:45 -06:00
kexec_elf.c
kexec_file.c memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED 2021-11-06 13:30:42 -07:00
kexec_internal.h kexec: move machine_kexec_post_load() to public interface 2021-02-22 12:33:26 +00:00
kexec.c kexec: avoid compat_alloc_user_space 2021-09-08 15:32:34 -07:00
kheaders.c
kmod.c modules: add CONFIG_MODPROBE_PATH 2021-05-07 00:26:33 -07:00
kprobes.c kprobe: move sysctl_kprobes_optimization to kprobes.c 2022-01-22 08:33:36 +02:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
latencytop.c
Makefile module: add in-kernel support for decompressing 2022-01-11 18:45:02 -08:00
module_decompress.c module: fix building with sysfs disabled 2022-02-16 12:51:32 -08:00
module_signature.c
module_signing.c
module-internal.h module: add in-kernel support for decompressing 2022-01-11 18:45:02 -08:00
module.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-03 11:20:34 -08:00
notifier.c notifier: Return an error when a callback has already been registered 2021-12-29 10:37:33 +01:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c padata: Remove repeated verbose license text 2021-08-27 16:30:18 +08:00
panic.c panic: remove oops_id 2022-01-20 08:52:55 +02:00
params.c kobject: remove kset from struct kset_uevent_ops callbacks 2021-12-28 11:26:18 +01:00
pid_namespace.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
pid.c pid: add pidfd_get_task() helper 2021-10-14 13:29:18 +02:00
profile.c exit: Remove profile_handoff_task 2022-01-08 12:43:57 -06:00
ptrace.c ptrace: Remove second setting of PT_SEIZED in ptrace_attach 2022-01-08 12:43:57 -06:00
range.c
reboot.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2021-11-12 11:53:16 -08:00
regset.c
relay.c
resource_kunit.c
resource.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
rseq.c KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest 2021-09-22 10:24:01 -04:00
scftorture.c scftorture: Always log error message 2021-12-07 16:36:17 -08:00
scs.c scs: Release kasan vmalloc poison in scs_free process 2021-09-30 09:37:27 +01:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-10 19:09:12 -08:00
signal.c signal, x86: Delay calling signals in atomic on RT enabled kernels 2022-03-04 14:58:54 +01:00
smp.c sched: Improve wake_up_all_idle_cpus() take #2 2021-10-22 15:32:46 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c genirq, softirq: Use in_hardirq() instead of in_irq() 2022-02-02 21:34:19 +01:00
stackleak.c gcc-plugins/stackleak: Use noinstr in favor of notrace 2022-02-03 17:02:21 -08:00
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2021-11-06 13:30:43 -07:00
static_call.c static_call: Fix static_call_text_reserved() vs __init 2021-07-05 10:46:33 +02:00
stop_machine.c stop_machine: Add caller debug info to queue_stop_cpus_work 2021-03-23 16:01:58 +01:00
sys_ni.c mm/mempolicy: wire up syscall set_mempolicy_home_node 2022-01-15 16:30:30 +02:00
sys.c mm: refactor vm_area_struct::anon_vma_name usage code 2022-03-05 11:08:32 -08:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting 2022-02-21 10:21:47 +01:00
task_work.c kasan: record task_work_add() call stack 2021-04-30 11:20:42 -07:00
taskstats.c
torture.c torture: Wake up kthreads after storing task_struct pointer 2022-02-01 17:24:39 -08:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-01-08 12:43:57 -06:00
ucount.c ucounts: Handle wrapping in is_ucounts_overlimit 2022-02-17 09:11:57 -06:00
uid16.c
uid16.h
umh.c kernel/umh.c: fix some spelling mistakes 2021-05-07 00:26:34 -07:00
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user_namespace.c ucounts: Fix systemd LimitNPROC with private users regression 2022-02-25 10:40:14 -06:00
user-return-notifier.c
user.c fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c watch_queue: Make comment about setting ->defunct more accurate 2022-03-11 10:17:13 -08:00
watchdog_hld.c
watchdog.c watchdog: move watchdog sysctl interface to watchdog.c 2022-01-22 08:33:34 +02:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00
workqueue.c Merge branch 'workqueue/for-5.16-fixes' into workqueue/for-5.17 2022-01-10 07:54:04 -10:00